refactor(@angular/build): co-locate vitest browser provider logic

Refactors the Vitest test runner to improve code organization and separation of concerns.

The browser-specific helper functions (`findBrowserProvider`, `normalizeBrowserName`, and `setupBrowserConfiguration`) are moved from the main `executor.ts` file into a new, dedicated `browser-provider.ts` file.

This cleanup allows the main executor to focus solely on its primary responsibility of managing the test execution lifecycle, while properly encapsulating the browser setup logic in a single, co-located file.

Author: clydin

packages/angular/build/src/builders/unit-test/runners/vitest/browser-provider.ts

@@ -0,0 +1,92 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+import { createRequire } from 'node:module';
+
+function findBrowserProvider(
+  projectResolver: NodeJS.RequireResolve,
+): import('vitest/node').BrowserBuiltinProvider | undefined {
+  // One of these must be installed in the project to use browser testing
+  const vitestBuiltinProviders = ['playwright', 'webdriverio'] as const;
+
+  for (const providerName of vitestBuiltinProviders) {
+    try {
+      projectResolver(providerName);
+
+      return providerName;
+    } catch {}
+  }
+
+  return undefined;
+}
+
+function normalizeBrowserName(browserName: string): string {
+  // Normalize browser names to match Vitest's expectations for headless but also supports karma's names
+  // e.g., 'ChromeHeadless' -> 'chrome', 'FirefoxHeadless' -> 'firefox'
+  // and 'Chrome' -> 'chrome', 'Firefox' -> 'firefox'.
+  const normalized = browserName.toLowerCase();
+
+  return normalized.replace(/headless$/, '');
+}
+
+export function setupBrowserConfiguration(
+  browsers: string[] | undefined,
+  debug: boolean,
+  projectSourceRoot: string,
+): { browser?: import('vitest/node').BrowserConfigOptions; errors?: string[] } {
+  if (browsers === undefined) {
+    return {};
+  }
+
+  const projectResolver = createRequire(projectSourceRoot + '/').resolve;
+  let errors: string[] | undefined;
+
+  try {
+    projectResolver('@vitest/browser');
+  } catch {
+    errors ??= [];
+    errors.push(
+      'The "browsers" option requires the "@vitest/browser" package to be installed within the project.' +
+        ' Please install this package and rerun the test command.',
+    );
+  }
+
+  const provider = findBrowserProvider(projectResolver);
+  if (!provider) {
+    errors ??= [];
+    errors.push(
+      'The "browsers" option requires either "playwright" or "webdriverio" to be installed within the project.' +
+        ' Please install one of these packages and rerun the test command.',
+    );
+  }
+
+  // Vitest current requires the playwright browser provider to use the inspect-brk option used by "debug"
+  if (debug && provider !== 'playwright') {
+    errors ??= [];
+    errors.push(
+      'Debugging browser mode tests currently requires the use of "playwright".' +
+        ' Please install this package and rerun the test command.',
+    );
+  }
+
+  if (errors) {
+    return { errors };
+  }
+
+  const browser = {
+    enabled: true,
+    provider,
+    headless: browsers.some((name) => name.toLowerCase().includes('headless')),
+
+    instances: browsers.map((browserName) => ({
+      browser: normalizeBrowserName(browserName),
+    })),
+  };
+
+  return { browser };
+}

packages/angular/build/src/builders/unit-test/runners/vitest/executor.ts

@@ -19,6 +19,7 @@ import type { FullResult, IncrementalResult } from '../../../application/results
 import { writeTestFiles } from '../../../karma/application_builder';
 import { NormalizedUnitTestBuilderOptions } from '../../options';
 import type { TestExecutor } from '../api';
+import { setupBrowserConfiguration } from './browser-provider';
 
 type VitestCoverageOption = Exclude<InlineConfig['coverage'], undefined>;
 
@@ -171,89 +172,6 @@ export class VitestExecutor implements TestExecutor {
   }
 }
 
-function findBrowserProvider(
-  projectResolver: NodeJS.RequireResolve,
-): import('vitest/node').BrowserBuiltinProvider | undefined {
-  // One of these must be installed in the project to use browser testing
-  const vitestBuiltinProviders = ['playwright', 'webdriverio'] as const;
-
-  for (const providerName of vitestBuiltinProviders) {
-    try {
-      projectResolver(providerName);
-
-      return providerName;
-    } catch {}
-  }
-
-  return undefined;
-}
-
-function normalizeBrowserName(browserName: string): string {
-  // Normalize browser names to match Vitest's expectations for headless but also supports karma's names
-  // e.g., 'ChromeHeadless' -> 'chrome', 'FirefoxHeadless' -> 'firefox'
-  // and 'Chrome' -> 'chrome', 'Firefox' -> 'firefox'.
-  const normalized = browserName.toLowerCase();
-
-  return normalized.replace(/headless$/, '');
-}
-
-function setupBrowserConfiguration(
-  browsers: string[] | undefined,
-  debug: boolean,
-  projectSourceRoot: string,
-): { browser?: import('vitest/node').BrowserConfigOptions; errors?: string[] } {
-  if (browsers === undefined) {
-    return {};
-  }
-
-  const projectResolver = createRequire(projectSourceRoot + '/').resolve;
-  let errors: string[] | undefined;
-
-  try {
-    projectResolver('@vitest/browser');
-  } catch {
-    errors ??= [];
-    errors.push(
-      'The "browsers" option requires the "@vitest/browser" package to be installed within the project.' +
-        ' Please install this package and rerun the test command.',
-    );
-  }
-
-  const provider = findBrowserProvider(projectResolver);
-  if (!provider) {
-    errors ??= [];
-    errors.push(
-      'The "browsers" option requires either "playwright" or "webdriverio" to be installed within the project.' +
-        ' Please install one of these packages and rerun the test command.',
-    );
-  }
-
-  // Vitest current requires the playwright browser provider to use the inspect-brk option used by "debug"
-  if (debug && provider !== 'playwright') {
-    errors ??= [];
-    errors.push(
-      'Debugging browser mode tests currently requires the use of "playwright".' +
-        ' Please install this package and rerun the test command.',
-    );
-  }
-
-  if (errors) {
-    return { errors };
-  }
-
-  const browser = {
-    enabled: true,
-    provider,
-    headless: browsers.some((name) => name.toLowerCase().includes('headless')),
-
-    instances: browsers.map((browserName) => ({
-      browser: normalizeBrowserName(browserName),
-    })),
-  };
-
-  return { browser };
-}
-
 function generateOutputPath(): string {
   const datePrefix = new Date().toISOString().replaceAll(/[-:.]/g, '');
   const uuidSuffix = randomUUID().slice(0, 8);